1. Field of the Invention
The present general inventive concept relates to a cooling fan assembly, and more particularly, to a cooling fan assembly to reduce a flow resistance and to maximize ventilation efficiency by converting a rotational directional flow component generated by rotation of vanes into an axial directional flow component.
2. Description of the Related Art
In general, axial fans used in machinery, electronic products, etc., are widely used for cooling various kinds of heating elements, and are comprised of a rotating shaft, rotating vanes engaged and combined with the rotating shaft, and a driving unit for providing a torque to the rotating shaft. An example of a conventional axial fan structure is disclosed in Korean Patent publication No. 10-2004-0095368 published on Nov. 15, 2004.
However, such a conventional technology has a problem in that though an air flow comprising an axial direction flow component and a rotational direction flow component is created by rotation of rotating vanes and the axial directional flow component performs an effective cooling function, the rotational directional flow component will be vanished to cause a loss, thereby reducing ventilation efficiency to some extent. Furthermore, as illustrated in FIG. 5, there is a problem that a discharged central portion is formed with an abrupt stage and the air flow cannot be facilitated, thereby increasing a resistance according to the air flow in the discharged central portion.